app:visibleGone无法在android数据绑定上解析 [英] app:visibleGone cannot resolve on android Databinding

问题描述

当我构建项目时.我在app:visibleGone

When I build the project. I'm getting error on app:visibleGone

我还启用了build.gradle中的dataBinding并使用android体系结构组件和mvvm. 项目targetSdkVersion是26和support lib version is 26.0.1.

I'm also enable true to dataBinding in build.gradle and using android architecture components and mvvm. project targetSdkVersion is 26 and support lib version is 26.0.1.

下面是错误消息

error: package com.****.****.databinding does not exist
error: cannot find symbol class ActivityMainBinding
Cannot find the setter for attribute 'app:visibleGone' with parameter type boolean on android.widget.Button.

这是我的 activity_main.xml

here is my activity_main.xml

<layout xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>

        <variable
            name="loading"
            type="boolean" />

    </data>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context="com.example.aungmyolwin.importdb.MainActivity">

        <Button
            android:id="@+id/btn_load_sql"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Load from SQL"
            app:visibleGone="@{!loading}"/>

        <Button
            android:id="@+id/btn_load_room"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Load from Room mapper"
            app:visibleGone="@{!loading}"/>

        <TextView
            android:id="@+id/tv_import_loading"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="Importing database...."
            app:visibleGone="@{loading}"/>


    </LinearLayout>
</layout>

ActivityMain.java

ActivityMain.java

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);

        binding.btnLoadRoom.setOnClickListener(this);
        binding.btnLoadSql.setOnClickListener(this);

        viewModels= ViewModelProviders.of(this).get(MainActivityViewModels.class);

    }
}

推荐答案

您需要为app:visibleGone创建自定义BindingAdapter(因为它不是可用的方法).
像

You need to create a custom BindingAdapter for app:visibleGone (because it is not a available method).
Like

public class BindingAdapters {
    @BindingAdapter("visibleGone")
    public static void showHide(View view, boolean show) {
        view.setVisibility(show ? View.VISIBLE : View.GONE);
    }
}

此外，如果您不想定义这样的方法，则可以这样做

Moreover, if you don't want to define a method like this, you can do like

<layout xmlns:app="http://schemas.android.com/apk/res-auto">
    <data>
        <variable
            name="loading"
            type="boolean" />
        <import type="android.view.View"/> <!-- remember to import -->
    </data>

    <LinearLayout >
        <Button
            android:visibility="@{loading ? View.GONE : View.VISIBLE}"
    </LinearLayout>
</layout>

这篇关于app:visibleGone无法在android数据绑定上解析的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！